🖼👁 Preview 1-4 images (compare)

This is a visual A/B tool with a slider you click and drag right on the preview to wipe between images - the same kind of before/after cursor you've seen on upscaler comparison sites, except it handles up to four images instead of just two, and it lives right inside your ComfyUI graph. The author's own example is a genuinely useful one: comparing an image at different resize percentages side by side, where a static grid of thumbnails makes subtle quality loss hard to spot but a wipe-cursor makes it obvious immediately.

Why you'd reach for it

Anywhere you're comparing outputs - two seeds, two samplers, a before/after fix, four different LoRA strengths - a wipe compare tells you more at a glance than four separate preview nodes stacked in a row ever will, because your eye can focus on one region and watch it change as you drag the cursor across it, instead of jumping between separate windows. It's the tool for "did that setting actually change anything," which is a question static previews are surprisingly bad at answering.

The inputs and outputs that matter

All four inputs are optional and interchangeable: image_1 through image_4, any of which you can connect or leave empty depending on how many images you're actually comparing - you don't need all four filled to use this node with two or three. One detail worth knowing that isn't obvious from the name: this node doesn't just preview, it also saves the images you feed it into your ComfyUI output directory, so it's pulling double duty as both a comparison tool and a save step. If you're specifically trying to avoid cluttering your output folder with test renders, that's worth keeping in mind.

The output is a single IMAGE, which you can chain onward if you want to keep working with whichever result you were comparing.

Installing it

Through ComfyUI Manager: search Bjornulf_custom_nodes, install, restart. Or by hand:

cd ComfyUI/custom_nodes
git clone https://github.com/justUmen/Bjornulf_custom_nodes

Install the shared requirements.txt afterward. This is a display/utility node with no heavy dependency of its own - it'll work on a minimal install of the pack.

Where people get burned

Feed it images at meaningfully different resolutions and the wipe comparison gets visually confusing fast - the slider is comparing pixel positions, so images that aren't the same size or aspect ratio won't line up the way you'd expect. If you're comparing an original against a resized or upscaled version, that's usually fine since the content lines up proportionally, but comparing two completely unrelated images (different subjects, different crops) defeats the point of the tool entirely - it's built for "same content, different processing," not general side-by-side browsing. And remember the save-to-output behavior mentioned above: if you're running this node repeatedly while iterating on settings, you'll accumulate saved copies in your output folder each time, not just a live preview.